Charlie Soap, Mankiller's husband, made the announcement Tuesday in a news release issued by the American Indian tribe. Soap says the 64-year-old Mankiller has stage 4 metastatic pancreatic cancer but offered no other details. He asked that the public respect the family's privacy.

Mankiller served as the tribe's chief from December 1985 until retiring in 1995. In September, Northeastern State University in Tahlequah named her as its first Sequoyah Institute Fellow.

Mankiller says in a statement that she is "mentally and spiritually prepared" for dealing with the cancer.